4 // Fraunhofer Institut fuer offene Kommunikationssysteme (FOKUS)
5 // Kompetenzzentrum fuer Satelitenkommunikation (SatCom)
6 // Stefan Bund <stefan.bund@fokus.fraunhofer.de>
8 // This program is free software; you can redistribute it and/or modify
9 // it under the terms of the GNU General Public License as published by
10 // the Free Software Foundation; either version 2 of the License, or
11 // (at your option) any later version.
13 // This program is distributed in the hope that it will be useful,
14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 // GNU General Public License for more details.
18 // You should have received a copy of the GNU General Public License
19 // along with this program; if not, write to the
20 // Free Software Foundation, Inc.,
21 // 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
24 \brief FileHandle public header
27 /** \defgroup handle_group The Handle Hierarchy
30 <map name="FhHierarchy">
31 <area shape="rect" alt="FileHandle" href="classsenf_1_1FileHandle.html" title="FileHandle" coords="247,1,345,27" />
32 <area shape="rect" alt="SocketHandle" href="classsenf_1_1SocketHandle.html" title="SocketHandle" coords="235,61,355,87" />
33 <area shape="rect" alt="ClientSocketHandle" href="classsenf_1_1ClientSocketHandle.html" title="ClientSocketHandle" coords="32,140,198,167" />
34 <area shape="rect" alt="ServerSocketHandle" href="classsenf_1_1ServerSocketHandle.html" title="ServerSocketHandle" coords="386,140,558,168" />
35 <area shape="rect" alt="ProtocolServerSocketHandle" href="classsenf_1_1ProtocolServerSocketHandle.html" title="ProtocolServerSocketHandle" coords="354,202,590,228" />
36 <area shape="rect" alt="ProtocolClientSocketHandle" href="classsenf_1_1ProtocolClientSocketHandle.html" title="ProtocolClientSocketHandle" coords="1,202,230,228" />
39 <img src="FhHierarchy.png" border="0" alt="FhHierarchy" usemap="#FhHierarchy">
43 The senf::FileHandle class is the base of a hierarchy of socket handle classes (realized as
44 templates). These classes provide an interface to the complete socket API. While going down the
45 inheritance hierarchy, the interface will be more and more complete.
47 The most complete interface is provided by senf::ProtocolClientSocketHandle and
48 senf::ProtocolServerSocketHandle. The template Arguments specifies the Protocol class of the
49 underlying socket type. These are the \e only classes having public constructors and are
50 therefore the only classes, which may be created by the library user. You will normally use
51 these classes by naming a specific socket typedef (e.g. senf::TCPv4ClientSocketHandle).
53 However, to aid writing flexible and generic code, the socket library provides the
54 senf::ClientSocketHandle and senf::ServerSocketHandle class templates. These templates implement
55 a family of closely related classes based on the specification of the socket policy. This policy
56 specification may be \e incomplete (see below). Instances of
57 senf::ClientSocketHandle/senf::ServerSocketHandle can be assigned and converted to different
58 ClientSocketHandle/ServerSocketHandle types as long as the policy specifications are compatible.
60 \attention It is very important, to (almost) always pass the socket handle <em>by
61 value</em>. The socket handle is a very lightweight class and designed to be used like an
62 ordinary built-in type. This is very important in combination with the policy interface.
64 \note The FileHandle hierarchy below the SocketHandle template is \e not meant to be user
65 extensible. To add new socket types, you should introduce new protocol and/or policy classes,
66 the SocketHandle classes should not be changed.
69 #ifndef HH_FileHandle_
70 #define HH_FileHandle_ 1
73 #include <memory> // std::auto_ptr
74 #include "../Utils/safe_bool.hh"
76 //#include "FileHandle.mpp"
77 ///////////////////////////////hh.p////////////////////////////////////////
78 #include "FileHandle.ih"
82 /// \addtogroup handle_group
85 /** \brief Basic file handle wrapper
87 senf::FileHandle provides a simple wrapper for arbitrary file handles. It exposes only a
88 minimal interface which does \e not include reading or writing (since some filehandles are
89 not readable or writable or only using special function calls like sendto).
91 The FileHandle class provides handle/body handling and uses automatic reference
92 counting. The senf::FileHandle instance is very lightweight and should be used like a
95 \attention You should mostly pass around senf::FileHandle objects by \e value and not by
98 The FileHandle abstraction is only applicable to real filehandles. It is \e not possible to
99 wrap any provider or consumer into a filehandle like interface using this wrapper. The
100 wrapper will forward some calls directly to the underlying API without relying on virtual
101 methods. This allows important members to be inlined.
103 It is not possible to use the senf::FileHandle class directly since it does not have any
104 public constructor. The FileHandle class is however the baseclass of all handle classes of
107 \section filehandle_new Writing senf::FileHandle derived classes
109 To build a new FileHandle type you need to derive from senf::FileHandle. The derived class
110 will have to call the protected FileHandle constructor passing a new senf::FileBody
111 instance. This instance may either be a simple senf::FileBody or a class derived from
115 : public safe_bool<FileHandle>
118 ///////////////////////////////////////////////////////////////////////////
121 ///////////////////////////////////////////////////////////////////////////
122 ///\name Structors and default members
127 // my default constructor
128 // default copy constructor
129 // default copy assignment
130 // default destructor
132 // no conversion constructors
135 ///////////////////////////////////////////////////////////////////////////
137 void close(); ///< Close filehandle
138 /**< \throws senf::SystemException */
139 void terminate(); ///< Close filehandle ignoring error conditions
141 bool readable() const; ///< Check, whether a read on the handle would not block
142 ///< (ignoring blocking state)
143 void waitReadable() const; ///< Wait, until read on the handle would not block (ignoring
145 bool writeable() const; ///< Check, whether a write on the handle would not block
146 ///< (ignoring blocking state)
147 void waitWriteable() const; ///< Wait, until a write on the handle would not block
148 ///< (ignoring blocking state)
150 bool blocking() const; ///< Return current blocking state
151 void blocking(bool status); ///< Set blocking state
153 bool eof() const; ///< Check EOF condition
154 /**< Depending on the socket type, this might never return \p
157 This member is somewhat problematic performance wise if
158 called frequently since it relies on virtual
159 functions. However, since the eof() handling is extremely
160 protocol dependent, a policy based implementation does not
162 bool valid() const; ///< Check filehandle validity
163 /**< Any operation besides valid() will fail on an invalid
166 bool boolean_test() const; ///< Short for valid() && ! eof()
167 /**< This is called when using a FileHandle instance in a boolean
170 See the performance comments for the eof() member */
172 int fd() const; ///< Return the raw FileHandle
174 static FileHandle cast_static(FileHandle handle); /**< \internal */
175 static FileHandle cast_dynamic(FileHandle handle); /**< \internal */
178 explicit FileHandle(std::auto_ptr<FileBody> body);
179 ///< create new FileHandle instance
180 /**< The FileHandle instance will take over ownership over the
181 given FileBody instance which must have been allocated using
182 \c new. To configure the FileHandle behavior, A derived class
183 may provide any class derived from FileBody here. */
185 explicit FileHandle(FileBody::ptr body);
187 FileBody & body(); ///< Access body
188 FileBody const & body() const; ///< Access body in const context
189 static FileBody & body(FileHandle & handle); ///< Access body of another FileHandle instance
190 static FileBody const & body(FileHandle const & handle); ///< Access body of another
191 ///< FileHandle instance in const context
193 void fd(int fd); ///< Set raw filehandle
198 friend class FileBody;
201 /** \brief Adapt FileHandle to senf::Scheduler
202 \related senf::FileHandle
206 This function will be called by the Scheduler to retrieve the file descriptor of the
209 int retrieve_filehandle(FileHandle handle);
215 ///////////////////////////////hh.e////////////////////////////////////////
216 #include "FileHandle.cci"
217 //#include "FileHandle.ct"
218 //#include "FileHandle.cti"
225 // c-file-style: "senf"
226 // indent-tabs-mode: nil
227 // ispell-local-dictionary: "american"
228 // compile-command: "scons -u test"
229 // comment-column: 40